Physician Spotlight

Kenneth Cohen, M.D. Director of Pediatric Neuro-Oncology and Clinical Director of Division of Pediatric Oncology Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Read More
What are Gliomas / What are Clinical Trials

What are Clinical Trials?

When your child is diagnosed with cancer, it is important to know all of the treatment options available in order to make the best decision. This may include clinical trials, which are research studies designed to evaluate new cancer treatment options. Clinical trials test the safety and effectiveness of treatments, many of which are only available through participating in a clinical trial. Trials evaluate new anti-cancer drugs, unique approaches to surgery and radiation therapy, and new combinations of treatments. In the United States, the Food and Drug Administration (FDA) oversees the conduct of clinical trials.

Are all clinical trials the same?

Development of new anticancer drugs and treatment strategies occurs in four phases. Each phase is designed to determine specific information about the potential new treatment such as its risks, safety, and effectiveness compared to standard therapy. The hope is that the new therapy will be an improvement over the previous standard therapy.

Phase I Trials

This phase is probably the most important step in the development of a new drug or therapy. Phase I therapy may produce anti-cancer effects and a small number of patients may benefit, however, the primary goals of this phase are to determine safety issues, which include:

  • The maximum tolerated dose of the treatment
  • The manner in which the drug works in the body
  • The toxic side effects related to different doses, and
  • Whether toxic side effects are reversible.

Phase I trials usually involve a small number of patients for whom other standard therapies have failed or no known alternative therapy is available. Upon completion of phase I trials, the information that has been gathered is used to begin phase II trials.

Phase II Trials

Phase II trials are designed to determine the effectiveness of the treatment in a specific patient population at the dose and schedules determined in phase I. These trials usually require a slightly higher number of patients than phase I trials. In general, all of the patients participating in a phase II trial will receive the treatment that is being investigated. Drugs or therapies that are shown to be active in phase II trials may become standard treatment or be further evaluated for effectiveness in phase III trials.

Phase III Trials

Phase III trials compare a new drug or therapy with a standard therapy in a randomized and controlled manner in order to determine proof of effectiveness. Phase III trials require a large number of patients to measure the statistical validity of the results because patient age, sex, race, and other unknown factors could affect the results. To obtain an adequate number of patients, several physicians (investigators) from different institutions typically participate in phase III clinical trials.

Phase IV Trials

Once the drug or treatment is approved and becomes part of standard therapy, the manufacturer of the drug may elect to initiate phase IV trials. This phase includes continued evaluation of the treatment effectiveness and monitoring of side effects as well as implementing studies to evaluate usefulness in different types of cancers.

What Clinical Trials are out there?

" is a registry of federally and privately supported clinical trials conducted in the United States and around the world. gives you information about a trial's purpose, who may participate, locations, and phone numbers for more details. This information should be used in conjunction with advice from health care professionals."  See:

Clinical Trials and Noteworthy Treatments for Brain Tumors

The Musella Foundation For Brain Tumor Research is a 501(c)3 non- profit organization dedicated to improving the quality of life and survival times for brain tumor patients by using computer technology to index brain tumor clinical trials, streamline the flow of information, organize the brain tumor community and raise money for brain tumor research. See: